Cable ties are well known devices and are used throughout the home and industry in a multitude of applications. The automotive industry, in particular, uses a large number of cable ties and straps during the manufacture and assembly of automotive vehicles. One particular use for cable ties by the automotive industry is to position and secure the wiring harnesses of the vehicle as they wind their way through the vehicle.
While the present invention will be described for exemplary purposes in an automotive application to position and secure a wiring harness at specified positions in an automotive vehicle, it is to be understood that the cable tie of the present invention can be utilized in any type of application which requires or could use a cable tie.
Wiring harnesses are used throughout the automotive vehicle to carry electrical power from the battery or alternator to the various electrical devices throughout the vehicle. Normally, power is supplied by the alternator and/or battery to a fuse block which in turn distributes the power to the variety of circuits responsible for the total operation of the vehicle. In order to simplify assembly, the automotive industry uses a number of wiring harnesses to distribute the power throughout the vehicle. A wiring harness is comprised of a plurality of wires grouped together and normally secured by some type of a sleeve. As each of the wiring harnesses traverses along its path through the vehicle, individual wires responsible for individual components either enter or leave the harness as the vicinity of each respective electrical component is reached. Due to this constant reduction and sometimes increase in the number of wires present in the wiring harness, the diameter of the wiring harness is an ever changing size.
The wiring harnesses are one of the first components to be assembled into the vehicle. When a wiring harness is assembled into a vehicle, it is necessary to position the wiring harness along a specified route to insure that the appropriate wire and wire connectors are positioned in the vicinity of their respective electrical components. In addition, the specified routing of the wiring harness insures that the wiring harness will not be damaged by or pinched between other components of the vehicle as the vehicle progresses along the assembly line. Once assembled in the vehicle, the positioning of the wire harness along its specified route also guarantees that during the operation of the vehicle the various components of the vehicle which are in motion will not damage the wiring harness.
In order to hold the wiring harnesses in their proper position along their specified routes through the vehicle, a plethora of clip and strap assemblies have been developed by the automotive manufacturers. Every time that the wiring harness changes in size, a new clip or strap needs to be designed. This requirement comes from the problem that during the life of the vehicle, the wiring harness must be adequately held in position. Strapping the wiring harness too tight can lead to abrasion of the insulation material by vibrations working on an edge of the strap. Strapping the wiring harness too loose can lead to slipping or movement of the wiring harness causing abrasion or an interference with other components of the vehicle. Therefore, every time a wire leaves or enters a wiring harness a new diameter clip or strap assembly is required. In addition to the complexity involved in the various sizes of clip and strap assemblies required, the complexity is further increased by the variety of ways in which the clip or strap assemblies interface with the vehicle. The cost to the automotive manufacturer for maintaining an individual active part number for each clip or strap assembly is substantial. By having a wide variety of clip and strap assemblies in varying sizes, each clip or strap assembly represents a separate part number with its associated individual costs of ordering, tracking, inventory, quality control, service and the like.
In an effort to reduce the complexity and the number of part numbers with their associated costs, the industry has looked at adjustable clip and strap assemblies. A variety of types of adjustable clip and strap assemblies have been tried by the automotive industry with varying degrees of success. One application involves the strapping of an attachment or securing device to the wiring harness itself. The securing device is then used to locate and secure the wiring harness to the vehicle by the use of integral hooks, clips, etc. These securing devices are normally positioned along the length of the wiring harness. When the prior art adjustable clip or strap assembly is being used to hold a securing device on the wiring harness itself, the proper amount of tension can not reliably be placed on the adjustable clip or strap assembly. Too much tension causes abrasion of insulating material by vibrations working on an edge of the strap as mentioned earlier and too little tension will not insure that the wiring harness will be adequately secured to the vehicle. This can cause slipping or movement of the wiring harness with the associated abrasion or interference. Another application tried for adjustable clip and strap assemblies has been applications where the wiring harness is going to be secured to a cross member or bracket in the vehicle. When the prior art adjustable clip or strap assembly is being used to secure the wiring harness to a bracket or cross member, the clip or strap assembly must be tight enough not to permit slippage of the wiring harness with respect to the strap or slippage of the strap along the cross member or bracket. The adjustable clip or strap assembly must also not be excessively tightened to cause abrasion of the insulation material. The tolerance band for acceptable tightening of the prior art adjustable strap has proven to be too small when a production environment is encountered.
Accordingly, what is needed is an adjustable style of tie strap which is capable of adequately holding both a securing device onto the wiring harness as well as being capable of securing the wiring harness to a bracket or cross member of the vehicle. The adjustable strap should have an adequate range of acceptable adjustment to simplify the proper attachment of the securing device to the wiring harness. In addition, the strap should present a cushioning surface to eliminate any abrasion of the insulation. The strap should also resist movement of the wiring harness when positioned around a bracket or other support member of the vehicle.